Magnetite–OmpA Nanobioconjugates as Cell-Penetrating Vehicles with Endosomal Escape Abilities

Abstract

Outer membrane protein A (OmpA) has been extensively studied in Gram-negative bacteria due to its relevance in the adhesion of pathogens to host cells and its surfactant capabilities. It consists of a hydrophobic β-barrel domain and a hydrophilic periplasmic domain, that confers OmpA an amphiphilic structure. This study aims to elucidate the capacity of Escherichia coli OmpA to translocate liposomal membranes and serve as a potential cell-penetrating vehicle. We immobilized OmpA on magnetite nanoparticles and investigated the possible functional changes exhibited by OmpA after immobilization. Liposomal intake was addressed using egg lecithin liposomes as a model, where magnetite–OmpA nanobioconjugates were able to translocate the liposomal membrane and caused a disruptive effect when subjected to a magnetic field. Nanobioconjugates showed both low cytotoxicity and hemolytic tendency. Additional interactions within the intracellular space led to altered viability results via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Confocal microscopy images revealed that immobilized nanoparticles effectively enter the cytoplasm of THP-1 and Vero cells by different routes, and, subsequently, some escape endosomes, lysosomes, and other intracellular compartments with relatively high efficiencies. This was demonstrated by co-localization analyses with LysoTracker green that showed Pearson correlations of about 80 and 28%.

Magnetite Nanoparticles Functionalized with RNases against Intracellular Infection of Pseudomonas aeruginosa

“…Moreover, they are considered safe due to their reduced hemolytic, platelet aggregation and cytotoxic effects. This was confirmed in the present study and agrees well with previous studies of our group [33,34,97].…”

Novel Bionanocompounds: Outer Membrane Protein A and Laccase Co-Immobilized on Magnetite Nanoparticles for Produced Water Treatment

“…Spectra were collected in the range of 4000–400 cm −1 with a spectral resolution of 2 cm −1 . The second derivative of magnetite-PEA-OmpA-Laccase bionanocompounds was calculated with the OriginPro8 Software and subsequently employed to determine alterations in the secondary structure of proteins after immobilization [ 2 , 60 ]. TGA was performed to estimate the thermal stability of magnetite nanoparticles and bionanocompounds.…”

“…NPs have unique properties, including nanometric size (which provides them with large surface areas), chemical stability in different environments, ease of synthesis, and low production costs [ 1 ]. NPs have been implemented for applications in a number industries including pharma [ 2 ], nutraceutical [ 3 ], food [ 4 ], agro-industrial [ 5 ], and cosmetics [ 6 ]. Moreover, they have been successfully explored as supports for the immobilization of various molecules of biological origin with the purpose of increasing their functionality and incorporating additional properties such as responsiveness to external stimuli; enhanced thermal, conformational, and long-term stability; and ease of transport and manipulation [ 7 , 8 , 9 , 10 , 11 ].…”

Tailoring Iron Oxide Nanoparticles for Efficient Cellular Internalization and Endosomal Escape

“…Similarly, in previous work by our group, we developed novel cell-penetrating nanobioconjugates by the immobilization of the outer membrane protein A (OmpA) of Escherichia coli on IONs. After 10 min of incubation, the obtained nanobioconjugates achieved endosomal escape levels above 25% in THP-1 cells, as estimated from their colocalization with endosomal compartments [ 268 ]. Recently, we also designed multifunctional orthopyridyl disulfide-PEG succimidyl ester (OPSS-PEG-NHS) coated IONs to enable the delivery of siRNA for silencing the BACE1 gene expression, as potential treatment of Alzheimer’s disease.…”

“…Hybrid ION/UCNP systems have been widely applied in cancer therapy, MRI and diagnosis, gene therapy, and drug delivery [ 308 ]. In general, the most prevalent host matrices for iron oxide core-shell nanoparticles include Y 2 O 3 , Y 2 O 2 S, LaF 3 , BaYF 5 , NaYF 4 , and NaGdF 4 , which have been doped with Yb 3+ /Tm 3+ and Yb 3+ /Er 3+ ions [ 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 , 238 , 239 , 240 , 241 , 242 , 243 , 244 , 245 , 246 , 247 , 248 , 249 , 250 , 251 , 252 , 253 , 254 , 255 , 256 , 257 , 258 , 259 , 260 , 261 , 262 , 263 , 264 , 265 , 266 , 267 , 268 , 269 , …”